Assessment of the Risk of Psychiatric Disorders, Use of Psychiatric Hospitals, and Receipt of Psychiatric Medication Among Patients With Lyme Neuroborreliosis in Denmark

Importance: The association of Lyme neuroborreliosis with the development of psychiatric disease is unknown and remains a subject of debate.

Objective: To investigate the risk of psychiatric disease, the percentage of psychiatric hospital inpatient and outpatient contacts, and the receipt of prescribed psychiatric medications among patients with Lyme neuroborreliosis compared with individuals in a matched comparison cohort.

Design, Setting, and Participants: This nationwide population-based matched cohort study included all residents of Denmark who received a positive result on an intrathecal antibody index test for Borrelia burgdorferi (patient cohort) between January 1, 1995, and December 31, 2015. Patients were matched by age and sex to a comparison cohort of individuals without Lyme neuroborreliosis from the general population of Denmark. Data were analyzed from February 2019 to March 2020.

Exposures: Diagnosis of Lyme neuroborreliosis, defined as a positive result on an intrathecal antibody index test for B burgdorferi.

Main Outcomes and Measures: The 0- to 15-year hazard ratios for the assignment of psychiatric diagnostic codes, the difference in the percentage of psychiatric inpatient and outpatient hospital contacts, and the difference in the percentage of prescribed psychiatric medications received among the patient cohort vs the comparison cohort.

Results: Among 2897 patients with Lyme neuroborreliosis (1646 men [56.8%]) and 28 970 individuals in the matched comparison cohort (16 460 men [56.8%]), the median age was 45.7 years (interquartile range [IQR], 11.5-62.0 years) for both groups. The risk of a psychiatric disease diagnosis and the percentage of hospital contacts for psychiatric disease were not higher among patients with Lyme neuroborreliosis compared with individuals in the comparison cohort. A higher percentage of patients with Lyme neuroborreliosis compared with individuals in the comparison cohort received anxiolytic (7.2% vs 4.7%; difference, 2.6%; 95% CI, 1.6%-3.5%), hypnotic and sedative (11.0% vs 5.3%; difference, 5.7%; 95% CI, 4.5%-6.8%), and antidepressant (11.4% vs 6.0%; difference, 5.4%; 95% CI, 4.3%-6.6%) medications within the first year after diagnosis, after which the receipt of psychiatric medication returned to the same level as the comparison cohort.

Conclusions and Relevance: In this population-based matched cohort study, patients with Lyme neuroborreliosis did not have an increased risk of developing psychiatric diseases that required hospital care or treatment with prescription medication. The increased receipt of psychiatric medication among patients with Lyme neuroborreliosis within the first year after diagnosis, but not thereafter, suggests that most symptoms associated with the diagnosis subside within a short period.